Tykerb

Rarely, people taking lapatinib have developed serious (possibly fatal) liver problems. Your doctor will perform liver function tests before and during treatment to monitor for this side effect. Keep all medical/lab appointments. Tell your doctor immediately if you develop symptoms of liver disease such as persistent nausea, stomach/abdominal pain, dark urine, or yellowing eyes/skin. Do not restart this medication if you have previously stopped taking it due to liver problems.

Uses

Lapatinib is used together with another medication (capecitabine) to treat a certain type of breast cancer (HER2-positive) that has not responded to the standard treatment. Lapatinib may also be used together with another medication (letrozole) to treat HER2-positive breast cancer in women after menopause. It works by slowing or stopping the growth of cancer cells.

How to use Tykerb

Read the Patient Information Leaflet provided by your pharmacist before you start using lapatinib and each time you get a refill. If you have any questions, consult your doctor or pharmacist.

Take this medication by mouth 1 hour before or 1 hour after a meal, usually once daily or as directed by your doctor. It is important that you do not take this medication more than once daily.

The dosage is based on your medical condition, response to treatment, and certain other drugs you may be taking.

Do not increase your dose or take this medication more often than prescribed. Your condition will not improve any faster, and the risk of serious side effects may be increased.

Avoid eating grapefruit or drinking grapefruit juice while being treated with this medication unless your doctor instructs you otherwise. Grapefruit can increase the amount of certain medications in your bloodstream. Consult your doctor or pharmacist for more details.

Since this drug can be absorbed through the skin and lungs, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

Follow your doctor's instructions on how to correctly take capecitabine or letrozole with lapatinib.

Diarrhea is a common side effect and may become severe. Tell your doctor immediately if diarrhea occurs or if you have signs of a severe loss of body water (dehydration) such as dizziness or decreased amount of urine. Your doctor should prescribe additional medication to help control your symptoms. If your diarrhea becomes severe, your doctor may need to stop or delay your lapatinib treatment.

Treatment with this drug may sometimes cause your hands/feet to develop a skin reaction called hand-foot syndrome (palmar-plantar erythrodysesthesia). Tell your doctor immediately if you experience swelling, pain, redness, peeling, blisters, or tingling/burning of the hands/feet. The symptoms can be made worse by heat/pressure on your hands/feet. Avoid prolonged sun exposure, tanning booths, and sunlamps, as well as unnecessary exposure to heat (e.g., hot dishwater, long hot baths). Use a sunscreen and wear protective clothing when outdoors. Avoid pressure on elbows, knees, and soles of feet (e.g., leaning on elbows, kneeling, taking long walks). Wear loose clothing and comfortable shoes. Depending on how severe your hand-foot syndrome is, your doctor may give you an additional medication to reduce the symptoms, or stop or delay your lapatinib treatment.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: unusual tiredness, shortness of breath, swelling ankles/feet.

Seek immediate medical attention if any of these rare but serious side effects occur: fast/pounding/irregular heartbeat, dizziness, fainting.

Precautions

Before taking lapatinib, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Lapatinib may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using lapatinib, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using lapatinib safely.

Older adults may be more sensitive to the side effects of this drug, especially QT prolongation (see above).

This medication is not recommended for use during pregnancy. It may harm an unborn baby. Therefore, it is important to prevent pregnancy while taking this medication. Consult your doctor for more details and to discuss the use of reliable forms of birth control (e.g., condoms, birth control pills) while taking this medication. If you become pregnant or think you may be pregnant, tell your doctor immediately.

It is not known whether this drug passes into breast milk. Because of the possible risk to the infant, breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.

Interactions

Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: digoxin, drugs affecting liver enzymes that remove lapatinib from your body (such as dexamethasone, cimetidine, St. John's wort, azole antifungals including itraconazole/ketoconazole, macrolide antibiotics including erythromycin/clarithromycin, HIV protease inhibitors including ritonavir/saquinavir, rifamycins including rifabutin, certain anti-seizure medicines including carbamazepine/phenytoin).

This drug can slow down the removal of other drugs from your body by affecting certain liver enzymes. These affected drugs include certain "statin" cholesterol medications (simvastatin, lovastatin, atorvastatin), tacrolimus, trazodone, digoxin, and cyclosporine, among others. Tell your doctor if you also take any of these medications.

Many drugs besides lapatinib may affect the heart rhythm (QT prolongation), including dofetilide, pimozide, procainamide, amiodarone, quinidine, sotalol, macrolide antibiotics (such as erythromycin), among others. Therefore, before using lapatinib, report all medications you are currently using to your doctor or pharmacist.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

Overdose

If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe diarrhea/vomiting.

Notes

Do not share this medication with others.

Laboratory and/or medical tests (e.g., EKG, electrolyte levels, heart/liver function) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

Missed Dose

For the best possible benefit, it is important to take each scheduled dose of this medication as directed. If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

Storage

Store at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Brief storage between 59-86 degrees F (15-30 degrees C) is permitted. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

Information last revised December 2013. Copyright(c) 2013 First Databank, Inc.

Treatment by Condition Related to Tykerb

Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, expect as may be authorized by the applicable terms of use.

CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.

Find a Drug or Condition

DrugConditionEnter a drug name. Use the arrow keys to navigate suggestions.